Tubing anchor



July 1, 1952 J. D. NIXON 2,603,153

v TUBING ANCHOR Filed Aug. 11, 1949 2 SHEETS-SHEET 1 Jeddy 0. NixonINVEN TOR.

J. D. NIXON TUBING ANCHOR July 15, 1952 2 SHEETS-SHEET 2 ATTORNEY FiledAug. 11, 1949 Patented July 15, 1952 TUBING ANCHOR J eddy D. Nixon, NewBraunfels, Tex., assignor of one-half to Wilson Foundry & MachineCompany, Houston, Tex., a corporation of Texas Application August 11,1949, Serial No. 109,701

'10 Claims. (01. 103-219) This invention relates to new and usefulimprovements in tubing anchors.

One object of the invention is to provide certain improvements upon thetubing anchor set forth in my Patent No. 1,941,813, issued January 2,1934, and particularly to employ an elastic sleeve for expanding theslips in place of the pistons set forth in said patent, whereby moreuniform distribution of the hydraulic pressure is obtained.

Another object of the invention is to provide, in connection with theslips, means for bleeding the liquid from the anchor and tubingthereabove disposed below the slips so that the liquid will wash up andbetween the slips, thus dislodging sand and any other accumulations andfreeing said slips for retraction.

Still another object of the invention is to provide a tubing anchorhaving a body provided with an annular chamber and windows extendingfrom the chamber together with elongate slips mounted in the windows anda fluid-responsive, elastic sleeve disposed in the body around themandrel and in engagement with the slips so as to expand the latter whensubjected to hydraulic pressure, thus providing an amplified pressurearea for each slip, whereby said slips are moved radially and uniformlythroughout their lengths.

Still another object of the invention is to provide an improved tubinganchor having slips actuated by an elastic, hydraulic sleeve mounted ina body which is provided with a liquid bleeding opening below the slipsand a mandrel mounted within the body having means for normally sealingthe bleeding opening and fastened to the body, whereby the body, uponbeing unfastened from the mandrel, may be moved vertically to expose thebleeding opening. a

A construction designed to carry out the invention will be hereinafterdescribed together with'other features of the invention.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawings,wherein an example of the invention is shown, and wherein:

Fig. 1 is an elevation of a tubing anchor constructed in accordance withthe invention,

Fig. 2 is an enlarged, horizontal, cross-sectional view taken on theline 2-2 of Fig. 1 and showing the'slips retracted, v a

Fig. 3 is a similarview showing the slips expanded,

Fig. 4 isa view of the upper half of the anchor, half in section andhalf in elevation, and

'Fig. 5 is a similar view of the lower half of the anchor.

In the drawings, the numeral I0 designates an axial core or tubularmandrel. The upper end of the mandrel has a free sliding fit in a capII.

A substantial distance from its upper end, the.

mandrel is formed with a circumferential enlargement or boss I2, I whichis externally screwthreaded and tapered downwardly. The upper end of themandrel is provided with a screwthreaded pin I3. Atubular base I4 has anaxial bore I4 in which the lower end of the mandrel is slidable and acounter bore I5 therebelow, whereby an annular shoulder I6 is formedbetween the bores and the lower end of the mandrel engages thisshoulder. The upper end of the base is formed into an annular shank II,the outer surface of which is tapered upwardly and screwthreaded. At thelower end of the shank the base is formed with an annular enlargement orboss I8 which extends radially of the shank so as to form a shoulder I9.

The mandrel'is slidable' in a thimble 20 just below the-boss I2, and isformed with an upstanding, annular tongue 2| having its inner surfacetapered and internally screw-threaded, as indicated at 22, to conformwith the inclination of the outer surface of the boss I2, and to receivethe-screw-threads thereof. The outer surface of the tongue is alsotapered upwardly and screwthreaded, as indicated at 23, to receive thescrewthreaded box 24 at the lower end of the cylindrical cap.

A cage 25 is formed of an upper collar 26 and a lower sleeve 29connected by webs or panels 33. The sleeve has a screw-threaded well 28in its lower end into which the shank I! is inserted. The collar has ascrew-threaded well 30in its upper end which is screwed onto the lowerscrewthreaded end of the thimble 20 below a shoulder 3| formed on anannular boss 32 which preferably has substantially the same diameter asthe boss I8. The cap I I, base I4, thimble 20, and cage 25 constitute abody 21.

The vertical edges of the webs are cut on chords with respect to themandrel I0 so as to provide spaced windows or openings 34. By 0bservingFigs. 2 and 3, it will be seen that the inner curved surfaces of thewebs 33 form the outer walls of an annular space or chamber 35 locatedbetween the webs and the mandrel I2 with its lower end defined [by thelower end of the shank I1, and its upper end defined by the lower end ofthe thimble 20. Within this space is confined a cylindrical, elasticsleeve or hydraulic expanding member 36 having inwardly directed,annular lips 31 at its upper and lower ends engaging the top and bottomwalls of said chamber.

These lips, when subjected to fluid pressure, form seals since the upperand lower ends of the sleeve engage the inner, annular surfaces of thecollar 26 and sleeve 29, which overhang the annular space or chamber.

As indicated in Fig. 1, the upper and lower ends of the windows 34 arerounded, as is indicated at 38. Transversely curved slips or grippinmembers 39 conforming generally to the contours of the windows arearranged to slide radially there in. The outer faces of the slips areprovided with arcuate, horizontal teeth 40. These teeth are V- shaped incross-section so that upon biting into the inner wall of the welltubing. (not shown) said teeth will hold equally as well against upwardor downward movement of the acres It .will be observed that thethickness of each slip is greater than the radial width of its window sothat when the slips are retracted, as shown in Fig. 2, the inner facesthereof will be in engagement with the outer cylindrical face of thesleeve 36, which will be unexpanded and spaced from the inner faces ofthe webs 33. The outer edges of the teeth 40 will lie substantially in acircle coincident with the outer edges of said webs.

A short distance above the lip 31, at the lower end of the sleeve 36, ahorizontal row of spaced apertures 4| are provided in the mandrel 12 sothat oil, gas or other fluid under pressure in the mandrel above saidapertures will flow therethrough into the chamber 35 within the sleeve36 and radially expand the latter. When this hydraulic expansion occursand the sleeve is extended radially, the slips 39 will be moved radiallyso as to project from the windows 34 beyond the bosses I8 and 32, as isbest shown in Fig. 3, and thus cause their teeth 40 to bite into theinner wall of the tubing. To limit the outward movement of the slips,and also to hold them within the windows 34, resilient retaining fingers42 are provided with hooks 43 which are arranged to engage over a flange43 at the upper end of the sleeve 21 and under a flange 44 on the bottomof the sleeve 29. The ends of the fingers are held positively betweensaid flanges and the shoulders i9 and 3!. Thesefingers extend along theouter surfaces of the sleeves 21 and 29 and have their free endsengaging in complementary recesses 45 in the upper and lower outer facesof the slips. The fingers being made of resilient metal and narrow willpermit an ample, radial movement of the slips, but will preventdislodgement of said slips from the windows.

It will be observed from the foregoing that the anchor includes certainmain members or ele-' ments which mayeach be formed of various parts.The mandrel includes elements l0, l2 and I3. The cap II has its upperend closed and loosely surrounding the mandrel. The cage member or bodyincludes the base M which is attached to the pump (not shown) or otherconnection and this base has the shank l1 whereby it is attached to thelower end of the cage 25, which latter has a collar 26 at its upper endscrewed onto the thimble 20 which has the annular tongue 2| at its upperend. This tongue being internally and externally screw-threaded isscrewed onto the boss I2 and into the bottom ofthecapll.

This invention being in some respects an improvement upon the tubinganchor set forth in my Patent No. 1,941,813, operates in a similarmanner. When the anchor is being lowered in the tubing, the fingers 42will hold theslips in a retracted position so that the anchor will havefree movement downwardly in said tubing. A screw-threaded pin l3 on thelower end of the base I4 is usually connected with the upper end of theWorking barrel of a reciprocating pump (not shown) and the bore l5 andthe mandrel I0 thus forms a part of the eduction conductor leading fromsaid pump, and until the pump is placed in operation, the bore [5 andthe mandrel will have fluid therein under static pressure, as isobvious. A particular advantage of the anchor herein set forth is thatvertically, elongated.

gripping areas are provided by the slips 39 and due to the hydraulicexpansion of the elastic sleeve 35, the pressure is uniformly appliedover the entire area. of each slip; therefore a more eificient anchoringis achieved.

It is obvious that the mandrel l0 and the tubing,'which is screwed ontothe upper end of the cap Ii containing a column of liquid, which mayextend several hundred feet above the anchor, the hydrostatic loadcreated thereby must be relieved before the pressure within the chamber35 can be reduced'to permit the slips 39 to be retracted or released. Inorder to release this column of fluid, provision is made to lift themandrel. Since the base M has its lower end fastened to the workingbarrel of the pump, rotation of the tubing will rotate the mandrel andconsequently the boss I2will be unscrewed (left hand threads) from thetongue 2! and the mandrel thus released; however the cage member is heldstationary. The mandrel is free to be lifted imtil the boss !2 engagesthe top of the cap and further upward movement is arrested. An annularrecess 46 is provided in the bore l4 of the base l4 below the boss l8and radial ports 41 extend from this recess through the wall of thehead. When the mandrel reaches the end of its upward movement, its lowerend will be above the ports 41 and therefore, the'column of fluid in themandrel will bleed oif through the recess 46 and the ports 41.

In order to prevent leakage of' the liquid through theports 41 whenthe'anchor is in its normal, operating position, packing rings 48 aredisposed in recesses 49 above and below said recess 46 so as to engagethe wall of the bore l4, and a similar ring 50 is disposed in a recess5! in the mandrel so as to engage the inner surface of. the thimble 20.By bleeding the anchor below the slips, it is obvious that the releasedfluid washes upward between the slips because of the channel shape ofthe webs 33 and thereby, any sand which would otherwise bind the slips,is washed into the casing. This arrangement will quickly free the slipsand permit the anchor to be raised in the well.

The foregoing description ofthe invention is explanatory thereof andvarious changes in the size, shape and materials, as well as in thedetails of the illustrated construction may be made, within the scope ofthe appended claims, without departing from the spirit of the invention.

'What I claim and desire to secure by Letters Patent is:

1. lnawell having a casing therein, a tubing anchor including, a tubularbody having windows therein, radially movable gripping members in thewindows of said body having teeth for gripping the casing when actuatedto hold said body against upwardand' downward movement, hydraulic meansin the body engaging the gripping members andres'p'onsiveto the pressureof the liquid from within theTbody, and a tubular mandrel within thehydraulic means having an opening for supplying liquid to said means,the body having a liquid bleeding opening below the grip-, ping membersnormally closed by the mandrel, the lower end of said mandrel beingmovable to a point above said bleeding opening to expose the bleedingopening at the lower end of said mandrel.

2. In a well having a casing therein, a tubing anchor as set forth inclaim 1, with resilient retaining fingers carried by the body and havingtheir ends overhanging the ends of the gripping members.

3. A well tubing anchor including, a tubular mandrel, an elongatecylindrical cage member surrounding the lower end of the mandrel andextending therebelow, the lower end of the mandrel having a flowconnection, a screw-threaded connection between the mandrel and the cagemember, whereby the mandrel may be disconnected from the cage member andmoved vertically thereof, the cage member having windows, elongate slipsmovable radially in the cage Windows, an elastic sleeve engaging theslips within the cage member surrounding the mandrel and having its endsabove and below the windows, the mandrel having an opening located tosupply a pressure fluid to the sleeve, the cage member hav ing a fluidoutlet normally closed by the mandrel and located to be exposed to fluidin the cage member when the mandrel is disconnected from the cage memberand its lower end moved to expose said outlet.

4. A well tubing anchor including, a tubular mandrel, an externallyscrew-threaded boss surrounding the mandrel intermediate its ends, a

cap slidable on the mandrel above the boss and having internal screwthreads, a cage member having an annular tongue at its upper endprovided with internal screw threads engaging the screw threads of theboss and external screw threads engaging the screw threads of the cap,whereby the boss may be unscrewed from the tongue and the mandrel movedupwardly through the cap and the cage member, the mandrel having apressure outlet in its side wall, slips in the cage member exposed onthe outer surface of said cage member, and an expanding element in thecage member engaging the slips and having an inner side exposed to fluidpressure from the mandrel.

5. A well tubing anchor including, a cage member having a connectingelement at its lower end, the cage member having windows intermediateits ends, outwardly movable elongate slips conlined in the windows ofthe cage member, expansible means in the cage member extending thelengths of they slips and free for uniform expansion throughout thelengths of the slips, whereby the slips are uniformly moved outwardly, amandrel extending down into the cage member through the expansible meansand having its bottom below said expansible means and terminating abovethe lower end of the cage member, the mandrel having a port constantlyopen to the expansi-ble means, and a detachable con.- nection betweenthe mandrel and the cage mernber.

6. A well tubing anchor as set forth in claim 5, wherein the expansiblemeans includes an elastic sleeve having its top and bottom sealed in thecage member above and below the upper and lower ends of the slips.

7. A well tubing anchor as set forth in claim 5, wherein the detachableconnection includes an upstanding element on the upper end of the cagemember screwed onto the mandre1 and detachable therefrom.

8. A well tubing anchor including, a cage member having a base at itslower end connected with a thimble at its upper end by spaced panels,said cage member having elongate vertical windows between the panels,elongate vertical slips in the windows movable radially of the cagemember, a tubular elastic sleeve in the cage member having its lower endsupported on the base below the windows and its upper end engaging thethimble above the windows, a tubular mandrel having its lower portionextending through the cage member and into the base and exposed to theinner wall of the sleeve, the mandrel having a fluid opening to theelastic sleeve, and a detachable connection between the upper end of thecage member and mandrel.

9. A well tubing anchor as set'forth in claim 8, and a cap surroundingthe mandrel above the detachable connection and detachably connected atits lower end to the thimble of the cage member.

10. A well tubing anchor as set forth in claim 8, wherein an upperpacking is interposed between the cage member and the mandrel above thefluid opening, an intermediate packing between the cage member and themandrel below said fluid opening, and a lower packing between the cagemember and the mandrel below the intermediate packing, the cage memberhaving an outlet opening normally between the intermediate and lowerpackings located to be exposed when the mandrel is detached from thecage member and moved upwardly.

JEDDY D. NIXON.

REFERENCES CITED The followingreferences are of record in the flle ofthis patent:

UNITED STATES PATENTS Number Name Date 1,874,688 Zucli et a1. Aug. 30,1932 1,941,813 Nixon et a1. Jan. 2, 1934 2,352,700 Ferris July 4,19442,370,832 Baker Mar. 6, 1945 2,467,822 Grifiin et a1 Apr. 19, 1949

